a standard is a criterion or something to aim for. If there were a standard for this it would be published somewhere authoritative. Perhaps you are asking if there is some set of figures that are generally considered acceptable of good?

However you go part way to explaining why there cannot be such a figure yourself when you refer to "type of user, infrastructure, apps, thin/fat client (i.e. a lot of variables)". Even from this list your "guideline" would have to evaluate the difference that each of these variables makes and to do that you would need to get much more explicit and definitive about things like "type of user".

There are two other very obvious reasons why such figures do not and cannot exist. Firstly you would need to have a clear and consistent definition of what an incident is, not from a book but from what is actually done (try to find out what every organization actually treats as an incident!).

But the biggest reason of all is that in practical terms the data is inaccessible. Think about the the effort required just to gather it, never mind all the clever things you would have to do to make it consistent across all the "lot of variables" you refer to. Just to give one example, how would you get consistent measures about the ease of use of different applications?_________________"Method goes far to prevent trouble in business: for it makes the task easy, hinders confusion, saves abundance of time, and instructs those that have business depending, both what to do and what to hope."
William Penn 1644-1718